C8051F352-GQR Silicon Laboratories Inc, C8051F352-GQR Datasheet - Page 136

• Manufacturer Part Number: C8051F352-GQR
• Description: IC 8051 MCU 8K FLASH 32LQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F35xr

Specifications of C8051F352-GQR

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 50MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 17
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x16b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Core: 8051
• Processor Series: C8051F3x
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 50 MHz
• Data Ram Size: 768 B
• Data Rom Size: 128 B
• On-chip Adc: Yes
• Number Of Programmable I/os: 17
• Number Of Timers: 4 bit
• Operating Supply Voltage: 2.7 V to 3.6 V
• Mounting Style: SMD/SMT
• A/d Bit Size: 16 bit
• A/d Channels Available: 8
• Height: 1.4 mm
• Interface Type: I2C, SMBus, SPI, UART
• Length: 7 mm
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Width: 7 mm
• For Use With: 336-1083 - DEV KIT FOR F350/351/352/353
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

C8051F350/1/2/3
17.4. System Clock Selection
The internal oscillator requires little start-up time and may be selected as the system clock immediately fol-
lowing the OSCICN write that enables the internal oscillator. External crystals and ceramic resonators typ-
ically require a start-up time before they are settled and ready for use. The Crystal Valid Flag (XTLVLD in
register OSCXCN) is set to ‘1’ by hardware when the external oscillator is settled. To avoid reading a
false XTLVLD, in crystal mode software should delay at least 1 ms between enabling the external
oscillator and checking XTLVLD. RC and C modes typically require no startup time.
The CLKSL[1:0] bits in register CLKSEL select which oscillator source is used as the system clock.
CLKSL[1:0] must be set to 01b for the system clock to run from the external oscillator; however the exter-
nal oscillator may still clock certain peripherals (timers, PCA) when the internal oscillator is selected as the
system clock. The system clock may be switched on-the-fly between the internal oscillator, external oscilla-
tor, and Clock Multiplier so long as the selected clock source is enabled and has settled.
Table 17.1. Oscillator Electrical Characteristics
–40 to +85 °C unless otherwise specified.
136
Internal Oscillator Frequency
Internal Oscillator Supply
Current (from V
Bits7–2: Unused. Read = 000000b; Write = don’t care.
Bits1–0: CLKSL1–0: System Clock Select
Bit7
—
R
Parameter
These bits select the system clock source.
DD
Bit6
—
R
)
CLKSL
00
01
10
11
SFR Definition 17.5. CLKSEL: Clock Select
Bit5
—
R
Bit4
—
R
Internal Oscillator (as determined by the
Reset Frequency
OSCICN.7 = 1
Conditions
IFCN bits in register OSCICN)
Rev. 1.1
Bit3
—
External Oscillator
R
Selected Clock
Clock Multiplier
RESERVED
Bit2
—
R
Min
24
—
R/W
Bit1
CLKSL
24.5
Typ
450
SFR Address:
R/W
Bit0
Max
25
—
0xA9
00000000
Reset Value
Units
MHz
µA